Introduction: Pancreatic neuroendocrine tumors (NETs) are rare malignancies, accounting for approximately 1-2% of all pancreatic cancers. There have been instances of synchronous carcinoid tumors or various other gastrointestinal NETs with concurrent secondary primary malignancies, however, there have not been previously documented cases of a pancreatic NET with concomitant colon adenocarcinoma presenting as acute pancreatitis.
Case Description/Methods: 73-year-old Caucasian female with no medical history, presented for 1 day of worsening right-sided abdominal pain. The pain began suddenly with no inciting event and she also reported an approximately 20-pound weight loss over the preceding months. Initial labs showed the patient had an elevated lipase, and computerized tomography (CT) of the abdomen/pelvis demonstrated extensive liver lesions consistent with metastatic disease. Additionally on the CT, the tail of the pancreas had a dilated pancreatic duct with a normal duct size in the proximal duct, indicating a pancreatic duct cut-off sign. Gastroenterology was consulted for further evaluation and an EGD with EUS was performed the following day revealing a 2cm x 3cm ill-defined mass in the head of the pancreas that was hypoechoic and heterogeneous in appearance. Multiple hypodense lesions were noted throughout the liver, and no pancreatic ductal dilatation was noted. Pathology revealed findings consistent with well differentiated grade 2 neuroendocrine tumor and was positive for CK-CAM5.2, CK7, CD56, chromogranin and synaptophysin, along with a KI-67 close to 20%. Tumor markers were also notable for a slightly elevated CA19-9 and a normal CEA. Colonoscopy was performed and notable for a 3cm descending colon polyp, which was later revealed to be well-differentiated adenocarcinoma with invasion into the submucosa. The patient was discharged with instructions to follow up outpatient with Hematology/Oncology, Surgical Oncology, and Gastroenterology, and is currently in the process of undergoing treatment.
Discussion: There are many causes for acute pancreatitis, with the most common being gallstones, alcohol, and medication-induced. A less frequently seen etiology is malignancy, and among the different types of pancreatic neoplasms, NETs are among the rarest. Although synchronous NETs and secondary primary malignancies have been documented, no cases have presented as acute pancreatitis. Prompt imaging, endoscopic procedures, and biopsies should be obtained in patients with potential NETs to expedite treatment.
